Appendix Ji The effect of deep ploughing on archaeological deposits. Hayton, East Yorkshire - a case study. Peter Halkon ©The University of Hull Department of History, 2001 Oxford Archaeology May 2002 (revised December 2002) THE EFFECT OF DEEP PLOUGHING ON ARCHAEOLOGICAL DEPOSITS. HAYTON, EAST YORKSHIRE – A CASE STUDY. Peter Halkon THE UNIVERSITY OF HULL Department of History November 2001 The effect of deep ploughing on archaeological deposits. Hayton, East Yorkshire - a case study Peter Halkon (University of Hull) Introduction Information included in this report is drawn from a detailed investigation of the Foulness Valley, East Yorkshire, initiated by the writer in 1980 and run jointly with Martin Millett since 1983. One of the great successes of the project has been the close relationship that has been built up with the farmers and landowners in the area of study, made easier by the writer’s own farming background. The aim here is not to castigate farmers for ploughing archaeological sites, but to contribute towards current proposals for the provision of subsidies to mitigate the effects of cultivation on the buried past. The farmers on whose land we have worked, especially those at Hayton, display a genuine interest in the archaeology on their farms and have been happy to discuss issues involved here. The report is structured as follows: 1. Outline of the Foulness valley project 2. Background to fieldwork at Hayton 3. Case study 1 - the Burnby Lane site 4. Case study 2 – the Roman roadside settlement 5. Conclusion and recommendations 1. Outline of the Foulness Valley project 1.1 Phase one: This consisted of an exploration of an 8x8km block around Holme-on-Spalding Moor, by fieldwalking a representative sample of each km square on c. 55 farms. Sites were then selected for research/training excavation (Halkon and Millett 1999). Discoveries included over 130 scatters and concentrations of Roman material presumed to be foci of settlement and industry, 30 pottery kiln sites and an extensive Iron Age iron industry. At Moore’s Farm, Welhambridge, one of the largest prehistoric heaps of iron slag in Britain, dating from c 300BC was excavated (Halkon 1997; Halkon and Millett 1999). Other discoveries included the Iron Age Hasholme log boat, (Millett and McGrail 1987). All this was tied in with a programme of aerial survey, study of soil maps and palaeo-environmental investigation. During our first excavations at Bursea House (Halkon and Millett 1999), we noticed the contrast between the condition of features protected by a grassy bank and the immediately adjacent ploughed field. The excavation of on an Iron Age enclosure containing a roundhouse at Bursea Grange, Holme-on-Spalding Moor, 1 (Halkon and Millett 1999) also revealed evidence for heavy erosion of the archaeological deposits caused by subsoiling of the sandy soils (see Figure 1). Figure 1. Excavations at Bursea Grange, Holme-on-Spalding Moor. Note the parallel grooves filled with dark soil left by the subsoiler. The dark curved feature in the centre is the foundation trench or eaves drip of a roundhouse. 1.2 Phase two: This phase investigated a Roman roadside settlement at Shiptonthorpe (Millett 1991). A full report on this is in final stages of preparation (Millett forthcoming). Fieldwalking was combined with soil chemistry and geophysical surveys (Taylor 1995) the latter revealing the clear plan of the road flanked by a series of plots used for housing, stock and a cemetery. During the following programme of research excavation, (1985-91), a section was cut across the Roman road and a complete plot next to it was excavated. This was found to contain a sequence of timber buildings and a waterhole, the latter containing evidence for structured deposition including well-preserved shoes, animal bones and pieces of wooden writing tablet. As at Bursea Grange, the excavation at Shiptonthorpe highlighted the damage caused by subsoiling. 2 2. Background to fieldwork at Hayton 2.1 Location, soils and land-use Hayton is situated 3km south-west of Pocklington, on gently undulating land at the foot of the western escarpment of the Yorkshire Wolds, at the eastern edge of the Vale of York. The present village is transected by the A1079, now the main road between York and Hull, which follows the approximate route of the Roman road between Brough on Humber and York (Margary 2e). The main soil type around Hayton is the Landbeach Series, which consists of light loamy gleyic brown calcareous earths, overlying glacio-fluvial gravels (King and Bradley 1987, 41). These are described by the Soil Survey of England and Wales as being generally well drained, “good general purpose soils”, and because of this are heavily cultivated. The main crops grown are wheat, barley, oilseed rape, potatoes and sugar beet (Middleton 1999). Because the soils can be stony within the plough zone in places, de-stoning is carried out, especially in preparation for potatoes, with obvious implications for archaeological deposits. Subsoiling is also regularly undertaken in order to overcome compaction (Bradley and King 1987), presenting a further threat. 2.2 Earlier archaeological work Although a few stray finds of Roman pottery were recorded in the 1950s, the main impetus for archaeological study in the Hayton area began with the discovery of an auxiliary fort from the air by St Joseph in 1974. It is clear from subsequent aerial photography and research that the fort was revealed as deeper modern ploughing removed the last vestiges of rig and furrow. The fort, which was excavated by Stephen Johnson for the Department of the Environment in the following year (Johnson 1978), was shown to be Flavian in date, though evidence for both Iron Age and Anglo-Saxon activity was found in the immediate vicinity. Johnson also investigated road-works during the dualling of the A1079 Trunk road, which suggested the presence of considerable Roman activity especially in the Grove Farm, Bridge Farm area, along the Roman road which runs just to the north of the modern route. Some fieldwalking was carried out during the 1980s by the writer, and by Bryan Sitch, with ERAS, following up metal detector finds brought into Hull Museums whilst he was working there (Sitch 1999). By this time Hayton had become especially popular with metal detector users and large numbers of Roman coins are recorded from various sites in the village (McLinden 1990). 3 3. Case Study 1 – The Burnby Lane site In March 1993, destoning in preparation for planting potatoes led to the third phase of our research in the Foulness valley. A farmer observed large quantities of tile, mortar, worked stone and some Roman pottery brought to the surface of a field on his neighbour’s land at Burnby Lane, Hayton (see Figure 2). He reported this to the writer, who identified the tile as coming from a hypocaust and organised a detailed gridded fieldwalking survey (Halkon 1993). The biggest concentration of ploughed up material was found on the gravel ridge by the lane, which runs parallel to Hayton Beck. Subsequent discussion with the landowner revealed that a Grimme Tornado destoner had been used here to break up clods of earth in areas of heavy land near the beck, to prevent them clogging up the potato harvester, making it easier to pick potatoes from the conveyor. Figure 2. The field at Burnby Lane, Hayton, in March 1993 soon after the discovery of the site. Note the mortar, tile and stone from the bath-house on the surface of the field. (Inset) a tile from the hypocaust pilae as found. Mortar is still adhering to it. Since the discovery of the ploughed-up hypocaust, we have examined a 3x3km landscape-block around Hayton, through further fieldwalking, geophysical and aerial survey, focussing research and training excavation on the Burnby Lane site. Here we have uncovered a series of Roman buildings with a bathhouse and excavated the Iron Age enclosure revealed in a geophysical survey. The full report is in the process of production and interim statements have been published on each season’s fieldwork (Halkon and Millett 1996; Halkon, and Millett and Taylor 1997 and 1998; Halkon et al 2000). 4 In 1995 (Millett and Halkon 1996), trenches were opened over the main geophysical anomalies and in the area of the densest concentration of tile and other debris brought to the surface during destoning. It quickly became apparent that the destoner had penetrated deeply into archaeological features and the regularly spaced parallel grooves left by the machine were clearly visible in trowelled surfaces. (Figures 3-5) Figure 3. An area of the 1995 excavation after ploughsoil stripping and trowelling, showing the effect of a destoner on buried features. Figure 4. The 1996 excavation showing a further area of destoning damage. 5 Figure 5. A detail of the hypocaust during the 1996 excavation. Note (right) the only pila left upstanding. The tile shown in Figure 2 (inset) is almost certainly from this stack. 4. Case study 2 – The Roman roadside settlement 4.1 Background The discovery of Roman material by Johnson during the dualling of the A1079, metal detector activity and earlier fieldwalking has been referred to above. The roadside settlement is situated on a prominent ridge of slightly stony, sandy loam in the Landbeach soil series, overlying chalk and flint gravel, rising to 30m OD. The Roman road itself appears to have been placed to take advantage of the this higher ground, as it runs along the ridge from the direction of Shiptonthorpe, and is clearly visible as crop mark on a series of aerial photographs taken by the writer since 1990. A large very dark loamy soil mark, most apparent after the field is freshly ploughed and contrasting with the lighter gravel soil on the ridge itself, indicates the most intensive area of settlement, which lies in a hollow to the south west of the gravel ridge.